1. Field of the Invention
The present invention relates to a mounting unit for a sub-frame, and more particularly, to a mounting unit for a sub-frame that is capable of improving assembly quality, reducing its weight, and improving NVH performance by improving ease of assembly between a side member and the sub-frame.
2. Description of Related Art
In general, a sub-frame is bolted to be assembled to a front side member in a center supportive type of vehicle.
FIG. 1 is a perspective view to describe a method for assembling a general front side member and a sub-frame.
Referring to FIG. 1, the sub-frame 101 is fastened by bolts 107 to a lower part of each of respective front side members 103 so as to be assembled thereto.
In the sub-frame 101, an engine (not shown) and a transmission (not shown) are disposed in front and rear directions, and buckling of the sub-frame 101 is induced to allow the engine to be dropped since the engine is designed to not be pushed toward a dash panel of a vehicle body as a rigid body, thereby guaranteeing collision safety.
The sub-frame 101 is fastened to the lower part of the front side member 103 by the bolt 107 through a mounting unit 105 for the sub-frame (hereinafter referred to as a “mounting unit”).
In order to fasten the sub-frame 101 to the lower part of the front side member 103, such a conventional mounting unit 105 includes a mounting bracket 109 that is bonded to the lower part of the front side member 103, and a pipe nut 111 that is installed between the mounting bracket 109 and the front side member 103.
That is, the sub-frame 101 is fastened to the front side member 103 through the pipe nut 111 and the bolt 107 under the mounting bracket 109.
However, such a conventional mounting unit 105 for the sub-frame has a structure in which the pipe nut 111 is simply fixed by the mounting bracket 109, thereby having a drawback of frequent defective assembly straightness and insufficient connection stiffness.
Accordingly, when a head-on collision of a vehicle occurs, the vehicle can be easily damaged.
The information disclosed in this Background of the Invention section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.